Tables are passed by reference - not an issue, but reassignment is not needed

[dcuny]

In the demo program xor.lua, you have the code:

local i = 0

while i<200 do
  brain = nn.train(brain,{1,1},{0})
  brain = nn.train(brain,{0,1},{1})
  brain = nn.train(brain,{1,0},{1})
  brain = nn.train(brain,{1,1},{0})
  i= i+1
  print("Epoch"..i)
end

In Lua, tables are passed by reference. Changes made to the table made in the routine nn.train() are being made to the same table referenced by brain. Returning the table from the function is not necessary.

The code below has the same result. Lua automatically creates i as a local variable when used in the loop, so there's no need to declare it:

for i = 1, 200 do
  nn.train(brain,{1,1},{0})
  nn.train(brain,{0,1},{1})
  nn.train(brain,{1,0},{1})
  nn.train(brain,{1,1},{0})
  print("Epoch"..i)
end